1. Field of the Invention
The present invention relates to foamed elastomeric polymers with a particular color scheme, specifically a visual camouflage appearance. More particularly the invention relates to a camouflage pattern characterized by distinct, randomly sized regions of various colors, each such region having nonangular borders and being a single, uniform color with substantially no blending of colors within it, with all color changes occurring at interfaces of distinct colored regions. The material is also free from marring by large gas pockets in and on the surface thereof. The invention further relates to a process for manufacturing the foamed elastomeric polymer.
2. Description of the Prior Art
Foamed materials have long been utilized in the polymers industries. Foamed polymers generally exhibit greater strength than an identical mass of the unfoamed polymer, and in many cases drastically reduces the thermal conductivity of the material because of the air contained in the cells of the foam.
Camouflage designs for foamed materials are likewise known. Such designs most frequently are applied by painting the outer surface of the foam. Attempts to achieve an internal camouflage appearance have resulted either in an unacceptable visual camouflage effect characterized by smeared, blended colors, or simply alternating bands of color with no random distribution of distinct areas of color, and thus no camouflage effect at all.
U.S. Pat. No. 4,417,932 to Brietscheidel et al. discloses a process for producing sheets of stratified material from synthetic resin foam particles. Foam particles are scattered onto a conveying means, and superficially preheated during conveyance to a temperature between 100.degree. C. and 160.degree. C. The particles are then fed into a free-fall zone, in which they are further heated to a temperature of at least 200.degree. C. After piling the particles onto a support surface, a sheetlike layer is formed by compacting the particles, and the sheet is then sized with simultaneous cooling.
U.S. Pat. No. 4,142,015 to Bienz discloses a thermal and visible camouflage for use on military equipment such as tanks. A layer of foamed plastic with a randomly varying insulating effect is applied to the outer surface of heat-generating equipment. Visual camouflage may be painted onto the plastic, or coatings under the plastic layer may also be used.
U.S. Pat. No. 4,243,709 to Morton discloses a method for making camouflage from sheets of multi-colored coated fabric. A film of camouflage polyvinyl chloride film is applied to each side of the fabric. The films are formed by applying plastisols of different colors to a carrier web, then overcoating the colored portions and any uncoated portions with a plastisol of another color. The films are then bonded to the fabric and the web is stripped from the outsides of the fabric. The multi-colored fabrics are cut into sheets which are attached to a net to make the camouflage screen.
U.S. Pat. No. 3,119,729 to Ljungbo discloses a flameproof camouflage net and method of manufacturing it. An apertured, flameproof sheet of plastic, or pieces thereof, are bonded by an adhesive to a net.
U.S. Pat. No. 2,054,848 to Bowker discloses a method of coloring thermoplastic materials to simulate the appearance of natural rocks and minerals, such as onyx. The thermoplastic is kneaded at elevated temperature with a solvent. The solvent is driven off and the material is formed into slabs by heated rolls. Coloring agents are applied to each slab, along with plasticizers as desired. An uncolored slab is superimposed over the colored slab, and the two slabs are worked by heated rolls until the desired effect is obtained.
A need thus exists for a camouflage material which has a nonrepetitive camouflage appearance on its surface and throughout its internal mass wherein virtually no blending of colors occurs at the interfaces of distinct colored regions.